Operation microscopes are used in a variety of medical disciplines in order to perform microsurgical work on fine structures. Thus, there are specific operation microscopes for ophthalmology, neurosurgery, dental medicine and numerous other fields.
In many cases, however, the direct view through the microscope is limited. Thus, in ophthalmology, hemorrhages may obstruct or prevent the view of the retina through the vitreous humor. In neurosurgery, in the event of access through the brain to a tumor, there is a desire to observe said tumor from the side or underside, in order to identify concrescence with blood vessels or nerves early on. In dental medicine, at the present time only few operations are actually performed with an operation microscope, since the rimose topology of the jaws allows only few areas of teeth or gum to be identified. It is important, furthermore, that a stereoscopic image is generated in order that the surgeon can estimate the depth of the operation field.
Microscopes are known which allow a particular mobility by virtue of a cardanic suspension and are used in neurosurgery. Such a microscope is described in DE-A-43 11 467. The problem of looking beside or behind a structure cannot, however, be solved by this microscope either. Moreover, this microscope cannot significantly improve the occlusion in dental medicine, since the viewing direction is limited from the outset.
The patent specifications DE-C-41 16 810, DE-C-42 25 507 and U.S. Pat. No. 5,496,261 in each case describe combinations of endoscopes with operation miscroscopes and operation microscope-like views on endoscopes. Although this results in stereoscopic vision through an endoscope and, if appropriate, the endoscope can be pivoted away in order to use the operation microscope on its own, these combinations of endoscopes and operation microscopes are not suitable for the purpose of use described above. The rigid coupling of microscope and endoscope does not allow free mobility of the endoscope tip, with the result that occlusions continue to occur. Moreover, it is possible for relative movements to occur between the patient, who is in each case only locally anaesthetized in ophthalmology and dental medicine, and the endoscope, as a result of which the rigid arrangement may not only lose the image but become a hazard for the patient.
Admittedly, DE-C-42 25 507 describes the use of flexible endoscopes enabling the last-mentioned disadvantage to be avoided. However, the citations reveal that the endoscope generates an image at a location corresponding to the location of the object if the microscope is used as a customary microscope. In this case, the endoscope with the imaging device by which the image to be observed is generated is situated on that side of the object plane which is remote from the objective lens. If, therefore, one wishes to observe the object previously observed through the endoscope directly with the microscope, not only does the endoscope have to be removed, but also the microscope has to be moved closer to the object and focused This means a considerable effect in respect of adjustment.